Stunted growth outside

Don't know much about Autoflowers, other than they belong outdoors in Northern Hemisphere climates. What i do know is Auto's are fussy as hell and one thing they HATE is being fucked with aka, transplanted. You need to plant your seedling in the pot you intend to finish in. If the plant doesn't seem to be doing anything, there could be not enough root space and it's root bound. Or your feeding not enough phosphorous and potassium. Or your pH is off and those elements are locked out. From my perspective, your plant looks undernourished and needs to be fed. Feed it a bloom formula higher in Phosphorous and Potassium. For example 5-18-12 And make sure your pH in your soil is 6.2 to 6.5 for maximum nutrient availability. Also, some autoflowering plants are low flyers, which means they are very short in stature. Your plant is budding now, and by the looks of the bud development on it, it's not going to grow taller any further. Autoflowers strikes again...

IMHO your auto is not going to grow much more because it started developing buds.